1. Field of the Invention
The present invention relates to a solid-state image capturing device including a semiconductor device for capturing image light from a subject by photoelectric conversion and a manufacturing method thereof; a solid-state image capturing apparatus having a high heat-resisting property and having the solid-state image capturing device mounted on a substrate by reflow soldering; and an electronic information device, such as a digital camera (e.g., digital video camera and digital still camera), an image input camera, a scanner, a facsimile machine and a camera-equipped cell phone device, having the solid-state image capturing apparatus as an image input device in an image capturing section of the electronic information device.
2. Description of the Related Art
Conventionally, in order to improve the light focusing rate of a light receiving section provided in CCD-type and CMOS-type solid-state image capturing devices for receiving image light from the subject, a corresponding on-chip lens is coupled to each light receiving section. Further, in order to improve the light focusing rate, an inner-layer lens may be provided in between the on-chip lens and the light receiving section. Further, in order to capture a color image, a color filter layer is provided under the location of the on-chip lens in a corresponding manner.
FIG. 3(a) is a top view schematically showing an exemplary structure of a conventional common solid-state image capturing device, and FIG. 3(b) is a longitudinal cross sectional view along the line A-A′ in FIG. 3(a).
In FIG. 3(a), a conventional solid-state image capturing device 100 is provided with a pixel section 110 and a peripheral circuit section 120, the pixel section 110 being an imaging area having multiple light receiving sections arranged in the center of the chip and the peripheral circuit section 120 being in the peripheral section around the pixel section 110.
In the pixel section 110, which is an imaging area, a plurality of photoelectric conversion elements (light receiving sections) for photoelectrically converting incident light to generate a signal charge, such as a photodiode, are provided in a matrix as a pixel section, and a CCD for reading out and transferring a signal charge from each photoelectric conversion element or a CMOS transistor for reading out a signal charge is further provided. As shown in FIG. 3(b), the photoelectric conversion elements are provided in a semiconductor layer 101, such as a silicon (Si) layer, and a gate electrode, which is a metal layer such as an Al layer, is provided thereon, and further a shading layer and/or a wiring is positioned on the gate electrode. Over the photoelectric conversion elements, an inner-layer lens 102, a color filter 103, a protective layer 104 and an on-chip lens 105, with inter layer films interposed between them, are laminated in this order in a corresponding manner over each photoelectric conversion element.
In addition, in the peripheral circuit section 120, a signal processing circuit is provided to conduct varieties of image signal processing for an image signal read out from each light receiving section in the pixel section 110. The signal processing circuit is formed with a layer shown as the semiconductor layer 101 in FIG. 3. Over the semiconductor layer 101, a color filter 103, a protective layer 104, and an on-chip lens 105 are further provided thereon.
FIG. 4(a) is an enlarged top view schematically showing a part of an exemplary structure of the peripheral circuit section 120 in FIG. 3(a), and FIG. 4(b) is a longitudinal cross sectional view along the line B-B′ in FIG. 4(a).
As shown in FIGS. 4(a) and 4(b), the peripheral circuit section 120 is provided with a bonding pad 107 as an external connection terminal, the bonding pad 107 being made from a semiconductor layer that is the same layer as the semiconductor layer 101, and the protective layer 104 is opened by an opening 104a over the bonding pad 107. The bonding pad 107, which is a square in a plane view, is provided at the bottom of the opening 104a. 
Reference 1: Japanese Laid-Open Publication No. 2006-165195